blob: 0edc44cb254e086c85690294d270305e5d2019b6 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright (C)2002 USAGI/WIDE Project
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +09003 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +09008 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090013 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070014 * You should have received a copy of the GNU General Public License
Jeff Kirshera99421d2013-12-06 09:13:39 -080015 * along with this program; if not, see <http://www.gnu.org/licenses/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -070016 *
17 * Authors
18 *
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090019 * Mitsuru KANDA @USAGI : IPv6 Support
Ian Morris67ba4152014-08-24 21:53:10 +010020 * Kazunori MIYAZAWA @USAGI :
21 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090022 *
Ian Morris67ba4152014-08-24 21:53:10 +010023 * This file is derived from net/ipv4/ah.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -070024 */
25
Joe Perchesf3213832012-05-15 14:11:53 +000026#define pr_fmt(fmt) "IPv6: " fmt
27
Steffen Klassert8631e9b2009-10-07 22:49:01 +000028#include <crypto/hash.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <linux/module.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090030#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <net/ip.h>
32#include <net/ah.h>
33#include <linux/crypto.h>
34#include <linux/pfkeyv2.h>
35#include <linux/string.h>
Steffen Klassert8631e9b2009-10-07 22:49:01 +000036#include <linux/scatterlist.h>
David S. Miller81aded22012-06-15 14:54:11 -070037#include <net/ip6_route.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include <net/icmp.h>
39#include <net/ipv6.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020040#include <net/protocol.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#include <net/xfrm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
Steffen Klassert8631e9b2009-10-07 22:49:01 +000043#define IPV6HDR_BASELEN 8
44
45struct tmp_ext {
Amerigo Wang07a93622012-10-29 16:23:10 +000046#if IS_ENABLED(CONFIG_IPV6_MIP6)
Steffen Klassert8631e9b2009-10-07 22:49:01 +000047 struct in6_addr saddr;
48#endif
49 struct in6_addr daddr;
50 char hdrs[0];
51};
52
53struct ah_skb_cb {
54 struct xfrm_skb_cb xfrm;
55 void *tmp;
56};
57
58#define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0]))
59
60static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags,
61 unsigned int size)
62{
63 unsigned int len;
64
65 len = size + crypto_ahash_digestsize(ahash) +
66 (crypto_ahash_alignmask(ahash) &
67 ~(crypto_tfm_ctx_alignment() - 1));
68
69 len = ALIGN(len, crypto_tfm_ctx_alignment());
70
71 len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash);
72 len = ALIGN(len, __alignof__(struct scatterlist));
73
74 len += sizeof(struct scatterlist) * nfrags;
75
76 return kmalloc(len, GFP_ATOMIC);
77}
78
79static inline struct tmp_ext *ah_tmp_ext(void *base)
80{
81 return base + IPV6HDR_BASELEN;
82}
83
84static inline u8 *ah_tmp_auth(u8 *tmp, unsigned int offset)
85{
86 return tmp + offset;
87}
88
89static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp,
90 unsigned int offset)
91{
92 return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1);
93}
94
95static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash,
96 u8 *icv)
97{
98 struct ahash_request *req;
99
100 req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash),
101 crypto_tfm_ctx_alignment());
102
103 ahash_request_set_tfm(req, ahash);
104
105 return req;
106}
107
108static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash,
109 struct ahash_request *req)
110{
111 return (void *)ALIGN((unsigned long)(req + 1) +
112 crypto_ahash_reqsize(ahash),
113 __alignof__(struct scatterlist));
114}
115
Eric Dumazeta50feda2012-05-18 18:57:34 +0000116static bool zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117{
118 u8 *opt = (u8 *)opthdr;
119 int len = ipv6_optlen(opthdr);
120 int off = 0;
121 int optlen = 0;
122
123 off += 2;
124 len -= 2;
125
126 while (len > 0) {
127
128 switch (opt[off]) {
129
Eldad Zack1de5a712012-05-17 06:00:25 +0000130 case IPV6_TLV_PAD1:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 optlen = 1;
132 break;
133 default:
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900134 if (len < 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 goto bad;
136 optlen = opt[off+1]+2;
137 if (len < optlen)
138 goto bad;
139 if (opt[off] & 0x20)
140 memset(&opt[off+2], 0, opt[off+1]);
141 break;
142 }
143
144 off += optlen;
145 len -= optlen;
146 }
147 if (len == 0)
Eric Dumazeta50feda2012-05-18 18:57:34 +0000148 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
150bad:
Eric Dumazeta50feda2012-05-18 18:57:34 +0000151 return false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152}
153
Amerigo Wang07a93622012-10-29 16:23:10 +0000154#if IS_ENABLED(CONFIG_IPV6_MIP6)
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700155/**
156 * ipv6_rearrange_destopt - rearrange IPv6 destination options header
157 * @iph: IPv6 header
158 * @destopt: destionation options header
159 */
160static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt)
161{
162 u8 *opt = (u8 *)destopt;
163 int len = ipv6_optlen(destopt);
164 int off = 0;
165 int optlen = 0;
166
167 off += 2;
168 len -= 2;
169
170 while (len > 0) {
171
172 switch (opt[off]) {
173
Eldad Zack1de5a712012-05-17 06:00:25 +0000174 case IPV6_TLV_PAD1:
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700175 optlen = 1;
176 break;
177 default:
178 if (len < 2)
179 goto bad;
180 optlen = opt[off+1]+2;
181 if (len < optlen)
182 goto bad;
183
184 /* Rearrange the source address in @iph and the
185 * addresses in home address option for final source.
186 * See 11.3.2 of RFC 3775 for details.
187 */
188 if (opt[off] == IPV6_TLV_HAO) {
189 struct in6_addr final_addr;
190 struct ipv6_destopt_hao *hao;
191
192 hao = (struct ipv6_destopt_hao *)&opt[off];
193 if (hao->length != sizeof(hao->addr)) {
Joe Perchese87cc472012-05-13 21:56:26 +0000194 net_warn_ratelimited("destopt hao: invalid header length: %u\n",
195 hao->length);
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700196 goto bad;
197 }
Alexey Dobriyan4e3fd7a2011-11-21 03:39:03 +0000198 final_addr = hao->addr;
199 hao->addr = iph->saddr;
200 iph->saddr = final_addr;
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700201 }
202 break;
203 }
204
205 off += optlen;
206 len -= optlen;
207 }
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900208 /* Note: ok if len == 0 */
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700209bad:
210 return;
211}
Masahide NAKAMURA136ebf02007-06-26 23:51:41 -0700212#else
213static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {}
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700214#endif
215
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216/**
217 * ipv6_rearrange_rthdr - rearrange IPv6 routing header
218 * @iph: IPv6 header
219 * @rthdr: routing header
220 *
221 * Rearrange the destination address in @iph and the addresses in @rthdr
222 * so that they appear in the order they will at the final destination.
223 * See Appendix A2 of RFC 2402 for details.
224 */
225static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr)
226{
227 int segments, segments_left;
228 struct in6_addr *addrs;
229 struct in6_addr final_addr;
230
231 segments_left = rthdr->segments_left;
232 if (segments_left == 0)
233 return;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900234 rthdr->segments_left = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235
236 /* The value of rthdr->hdrlen has been verified either by the system
237 * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming
238 * packets. So we can assume that it is even and that segments is
239 * greater than or equal to segments_left.
240 *
241 * For the same reason we can assume that this option is of type 0.
242 */
243 segments = rthdr->hdrlen >> 1;
244
245 addrs = ((struct rt0_hdr *)rthdr)->addr;
Alexey Dobriyan4e3fd7a2011-11-21 03:39:03 +0000246 final_addr = addrs[segments - 1];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247
248 addrs += segments - segments_left;
249 memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs));
250
Alexey Dobriyan4e3fd7a2011-11-21 03:39:03 +0000251 addrs[0] = iph->daddr;
252 iph->daddr = final_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253}
254
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700255static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256{
257 union {
258 struct ipv6hdr *iph;
259 struct ipv6_opt_hdr *opth;
260 struct ipv6_rt_hdr *rth;
261 char *raw;
262 } exthdr = { .iph = iph };
263 char *end = exthdr.raw + len;
264 int nexthdr = iph->nexthdr;
265
266 exthdr.iph++;
267
268 while (exthdr.raw < end) {
269 switch (nexthdr) {
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700270 case NEXTHDR_DEST:
271 if (dir == XFRM_POLICY_OUT)
272 ipv6_rearrange_destopt(iph, exthdr.opth);
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900273 case NEXTHDR_HOP:
274 if (!zero_out_mutable_opts(exthdr.opth)) {
Joe Perchesba7a46f2014-11-11 10:59:17 -0800275 net_dbg_ratelimited("overrun %sopts\n",
276 nexthdr == NEXTHDR_HOP ?
277 "hop" : "dest");
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900278 return -EINVAL;
279 }
280 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281
282 case NEXTHDR_ROUTING:
283 ipv6_rearrange_rthdr(iph, exthdr.rth);
284 break;
285
Ian Morris67ba4152014-08-24 21:53:10 +0100286 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 return 0;
288 }
289
290 nexthdr = exthdr.opth->nexthdr;
291 exthdr.raw += ipv6_optlen(exthdr.opth);
292 }
293
294 return 0;
295}
296
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000297static void ah6_output_done(struct crypto_async_request *base, int err)
298{
299 int extlen;
300 u8 *iph_base;
301 u8 *icv;
302 struct sk_buff *skb = base->data;
303 struct xfrm_state *x = skb_dst(skb)->xfrm;
304 struct ah_data *ahp = x->data;
305 struct ipv6hdr *top_iph = ipv6_hdr(skb);
306 struct ip_auth_hdr *ah = ip_auth_hdr(skb);
307 struct tmp_ext *iph_ext;
308
309 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
310 if (extlen)
311 extlen += sizeof(*iph_ext);
312
313 iph_base = AH_SKB_CB(skb)->tmp;
314 iph_ext = ah_tmp_ext(iph_base);
315 icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen);
316
317 memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
318 memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
319
320 if (extlen) {
Amerigo Wang07a93622012-10-29 16:23:10 +0000321#if IS_ENABLED(CONFIG_IPV6_MIP6)
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000322 memcpy(&top_iph->saddr, iph_ext, extlen);
323#else
324 memcpy(&top_iph->daddr, iph_ext, extlen);
325#endif
326 }
327
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000328 kfree(AH_SKB_CB(skb)->tmp);
329 xfrm_output_resume(skb, err);
330}
331
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
333{
334 int err;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000335 int nfrags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 int extlen;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000337 u8 *iph_base;
338 u8 *icv;
339 u8 nexthdr;
340 struct sk_buff *trailer;
341 struct crypto_ahash *ahash;
342 struct ahash_request *req;
343 struct scatterlist *sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 struct ipv6hdr *top_iph;
345 struct ip_auth_hdr *ah;
346 struct ah_data *ahp;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000347 struct tmp_ext *iph_ext;
Fan Du26dd70c2014-01-18 09:54:26 +0800348 int seqhi_len = 0;
349 __be32 *seqhi;
350 int sglists = 0;
351 struct scatterlist *seqhisg;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000352
353 ahp = x->data;
354 ahash = ahp->ahash;
355
Ian Morrise5d08d72014-11-23 21:28:43 +0000356 err = skb_cow_data(skb, 0, &trailer);
357 if (err < 0)
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000358 goto out;
359 nfrags = err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360
Herbert Xu7b277b12007-10-10 15:44:06 -0700361 skb_push(skb, -skb_network_offset(skb));
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000362 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
363 if (extlen)
364 extlen += sizeof(*iph_ext);
365
Fan Du26dd70c2014-01-18 09:54:26 +0800366 if (x->props.flags & XFRM_STATE_ESN) {
367 sglists = 1;
368 seqhi_len = sizeof(*seqhi);
369 }
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000370 err = -ENOMEM;
Fan Du26dd70c2014-01-18 09:54:26 +0800371 iph_base = ah_alloc_tmp(ahash, nfrags + sglists, IPV6HDR_BASELEN +
372 extlen + seqhi_len);
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000373 if (!iph_base)
374 goto out;
375
376 iph_ext = ah_tmp_ext(iph_base);
Fan Du26dd70c2014-01-18 09:54:26 +0800377 seqhi = (__be32 *)((char *)iph_ext + extlen);
378 icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000379 req = ah_tmp_req(ahash, icv);
380 sg = ah_req_sg(ahash, req);
Fan Du26dd70c2014-01-18 09:54:26 +0800381 seqhisg = sg + nfrags;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000382
383 ah = ip_auth_hdr(skb);
384 memset(ah->auth_data, 0, ahp->icv_trunc_len);
385
Herbert Xu007f0212007-10-09 13:25:59 -0700386 top_iph = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 top_iph->payload_len = htons(skb->len - sizeof(*top_iph));
388
Herbert Xu007f0212007-10-09 13:25:59 -0700389 nexthdr = *skb_mac_header(skb);
390 *skb_mac_header(skb) = IPPROTO_AH;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
392 /* When there are no extension headers, we only need to save the first
393 * 8 bytes of the base IP header.
394 */
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000395 memcpy(iph_base, top_iph, IPV6HDR_BASELEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397 if (extlen) {
Amerigo Wang07a93622012-10-29 16:23:10 +0000398#if IS_ENABLED(CONFIG_IPV6_MIP6)
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000399 memcpy(iph_ext, &top_iph->saddr, extlen);
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900400#else
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000401 memcpy(iph_ext, &top_iph->daddr, extlen);
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900402#endif
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700403 err = ipv6_clear_mutable_options(top_iph,
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000404 extlen - sizeof(*iph_ext) +
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700405 sizeof(*top_iph),
406 XFRM_POLICY_OUT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 if (err)
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000408 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 }
410
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 ah->nexthdr = nexthdr;
412
413 top_iph->priority = 0;
414 top_iph->flow_lbl[0] = 0;
415 top_iph->flow_lbl[1] = 0;
416 top_iph->flow_lbl[2] = 0;
417 top_iph->hop_limit = 0;
418
Herbert Xu87bdc482007-10-10 15:45:25 -0700419 ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420
421 ah->reserved = 0;
422 ah->spi = x->id.spi;
Steffen Klassert1ce36442011-03-08 00:06:31 +0000423 ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
Herbert Xub7c65382007-10-09 13:33:35 -0700424
Fan Du26dd70c2014-01-18 09:54:26 +0800425 sg_init_table(sg, nfrags + sglists);
Jason A. Donenfeld753b04d2017-06-04 04:16:23 +0200426 err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
427 if (unlikely(err < 0))
428 goto out_free;
Herbert Xub7c65382007-10-09 13:33:35 -0700429
Fan Du26dd70c2014-01-18 09:54:26 +0800430 if (x->props.flags & XFRM_STATE_ESN) {
431 /* Attach seqhi sg right after packet payload */
432 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
433 sg_set_buf(seqhisg, seqhi, seqhi_len);
434 }
435 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len);
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000436 ahash_request_set_callback(req, 0, ah6_output_done, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000438 AH_SKB_CB(skb)->tmp = iph_base;
439
440 err = crypto_ahash_digest(req);
441 if (err) {
442 if (err == -EINPROGRESS)
443 goto out;
444
445 if (err == -EBUSY)
446 err = NET_XMIT_DROP;
447 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 }
449
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000450 memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
451 memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
452
453 if (extlen) {
Amerigo Wang07a93622012-10-29 16:23:10 +0000454#if IS_ENABLED(CONFIG_IPV6_MIP6)
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000455 memcpy(&top_iph->saddr, iph_ext, extlen);
456#else
457 memcpy(&top_iph->daddr, iph_ext, extlen);
458#endif
459 }
460
461out_free:
462 kfree(iph_base);
463out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 return err;
465}
466
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000467static void ah6_input_done(struct crypto_async_request *base, int err)
468{
469 u8 *auth_data;
470 u8 *icv;
471 u8 *work_iph;
472 struct sk_buff *skb = base->data;
473 struct xfrm_state *x = xfrm_input_state(skb);
474 struct ah_data *ahp = x->data;
475 struct ip_auth_hdr *ah = ip_auth_hdr(skb);
476 int hdr_len = skb_network_header_len(skb);
477 int ah_hlen = (ah->hdrlen + 2) << 2;
478
479 work_iph = AH_SKB_CB(skb)->tmp;
480 auth_data = ah_tmp_auth(work_iph, hdr_len);
481 icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);
482
Ian Morris67ba4152014-08-24 21:53:10 +0100483 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000484 if (err)
485 goto out;
486
Nick Bowlerb7ea81a2011-11-08 12:12:45 +0000487 err = ah->nexthdr;
488
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000489 skb->network_header += ah_hlen;
490 memcpy(skb_network_header(skb), work_iph, hdr_len);
491 __skb_pull(skb, ah_hlen + hdr_len);
Li RongQinga9403f82013-01-08 15:41:12 +0800492 if (x->props.mode == XFRM_MODE_TUNNEL)
493 skb_reset_transport_header(skb);
494 else
495 skb_set_transport_header(skb, -hdr_len);
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000496out:
497 kfree(AH_SKB_CB(skb)->tmp);
498 xfrm_input_resume(skb, err);
499}
500
501
502
Herbert Xue6956332006-04-01 00:52:46 -0800503static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504{
505 /*
506 * Before process AH
507 * [IPv6][Ext1][Ext2][AH][Dest][Payload]
508 * |<-------------->| hdr_len
509 *
510 * To erase AH:
511 * Keeping copy of cleared headers. After AH processing,
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700512 * Moving the pointer of skb->network_header by using skb_pull as long
513 * as AH header length. Then copy back the copy as long as hdr_len
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 * If destination header following AH exists, copy it into after [Ext2].
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900515 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 * |<>|[IPv6][Ext1][Ext2][Dest][Payload]
517 * There is offset of AH before IPv6 header after the process.
518 */
519
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000520 u8 *auth_data;
521 u8 *icv;
522 u8 *work_iph;
523 struct sk_buff *trailer;
524 struct crypto_ahash *ahash;
525 struct ahash_request *req;
526 struct scatterlist *sg;
Herbert Xu87bdc482007-10-10 15:45:25 -0700527 struct ip_auth_hdr *ah;
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700528 struct ipv6hdr *ip6h;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529 struct ah_data *ahp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 u16 hdr_len;
531 u16 ah_hlen;
532 int nexthdr;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000533 int nfrags;
534 int err = -ENOMEM;
Fan Du8d6da6f2014-01-18 09:54:27 +0800535 int seqhi_len = 0;
536 __be32 *seqhi;
537 int sglists = 0;
538 struct scatterlist *seqhisg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539
540 if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr)))
541 goto out;
542
543 /* We are going to _remove_ AH header to keep sockets happy,
544 * so... Later this can change. */
Pravin B Shelar14bbd6a2013-02-14 09:44:49 +0000545 if (skb_unclone(skb, GFP_ATOMIC))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 goto out;
547
Herbert Xu7aa68cb2007-10-17 21:30:07 -0700548 skb->ip_summed = CHECKSUM_NONE;
549
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000550 hdr_len = skb_network_header_len(skb);
Herbert Xu87bdc482007-10-10 15:45:25 -0700551 ah = (struct ip_auth_hdr *)skb->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 ahp = x->data;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000553 ahash = ahp->ahash;
554
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 nexthdr = ah->nexthdr;
556 ah_hlen = (ah->hdrlen + 2) << 2;
557
Herbert Xu87bdc482007-10-10 15:45:25 -0700558 if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) &&
559 ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len))
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900560 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561
562 if (!pskb_may_pull(skb, ah_hlen))
563 goto out;
564
Ian Morrise5d08d72014-11-23 21:28:43 +0000565 err = skb_cow_data(skb, 0, &trailer);
566 if (err < 0)
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000567 goto out;
568 nfrags = err;
569
Dang Hongwu4b0ef1f22011-01-11 07:13:33 +0000570 ah = (struct ip_auth_hdr *)skb->data;
571 ip6h = ipv6_hdr(skb);
572
573 skb_push(skb, hdr_len);
574
Fan Du8d6da6f2014-01-18 09:54:27 +0800575 if (x->props.flags & XFRM_STATE_ESN) {
576 sglists = 1;
577 seqhi_len = sizeof(*seqhi);
578 }
579
580 work_iph = ah_alloc_tmp(ahash, nfrags + sglists, hdr_len +
581 ahp->icv_trunc_len + seqhi_len);
Julia Lawall25105052015-08-23 02:11:21 +0200582 if (!work_iph) {
583 err = -ENOMEM;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000584 goto out;
Julia Lawall25105052015-08-23 02:11:21 +0200585 }
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000586
Fan Du8d6da6f2014-01-18 09:54:27 +0800587 auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len);
588 seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len);
589 icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000590 req = ah_tmp_req(ahash, icv);
591 sg = ah_req_sg(ahash, req);
Fan Du8d6da6f2014-01-18 09:54:27 +0800592 seqhisg = sg + nfrags;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000593
594 memcpy(work_iph, ip6h, hdr_len);
595 memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
596 memset(ah->auth_data, 0, ahp->icv_trunc_len);
597
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700598 if (ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN))
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000599 goto out_free;
600
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700601 ip6h->priority = 0;
602 ip6h->flow_lbl[0] = 0;
603 ip6h->flow_lbl[1] = 0;
604 ip6h->flow_lbl[2] = 0;
605 ip6h->hop_limit = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606
Fan Du8d6da6f2014-01-18 09:54:27 +0800607 sg_init_table(sg, nfrags + sglists);
Jason A. Donenfeld753b04d2017-06-04 04:16:23 +0200608 err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
609 if (unlikely(err < 0))
610 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611
Fan Du8d6da6f2014-01-18 09:54:27 +0800612 if (x->props.flags & XFRM_STATE_ESN) {
613 /* Attach seqhi sg right after packet payload */
614 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
615 sg_set_buf(seqhisg, seqhi, seqhi_len);
616 }
617
618 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len);
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000619 ahash_request_set_callback(req, 0, ah6_input_done, skb);
620
621 AH_SKB_CB(skb)->tmp = work_iph;
622
623 err = crypto_ahash_digest(req);
624 if (err) {
625 if (err == -EINPROGRESS)
626 goto out;
627
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000628 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 }
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800630
Ian Morris67ba4152014-08-24 21:53:10 +0100631 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0;
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800632 if (err)
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000633 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700635 skb->network_header += ah_hlen;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000636 memcpy(skb_network_header(skb), work_iph, hdr_len);
Herbert Xu31a4ab92006-05-27 23:06:13 -0700637 __skb_pull(skb, ah_hlen + hdr_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638
Li RongQinga9403f82013-01-08 15:41:12 +0800639 if (x->props.mode == XFRM_MODE_TUNNEL)
640 skb_reset_transport_header(skb);
641 else
642 skb_set_transport_header(skb, -hdr_len);
643
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000644 err = nexthdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000646out_free:
647 kfree(work_iph);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648out:
Herbert Xu07d4ee52006-08-20 14:24:50 +1000649 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650}
651
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100652static int ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
653 u8 type, u8 code, int offset, __be32 info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654{
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800655 struct net *net = dev_net(skb->dev);
Ian Morris67ba4152014-08-24 21:53:10 +0100656 struct ipv6hdr *iph = (struct ipv6hdr *)skb->data;
657 struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 struct xfrm_state *x;
659
Steffen Klassertb3b2b9e2013-09-10 13:43:09 +0200660 if (type != ICMPV6_PKT_TOOBIG &&
David S. Millerec18d9a2012-07-12 00:25:15 -0700661 type != NDISC_REDIRECT)
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100662 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663
Jamal Hadi Salimbd557752010-02-22 16:20:22 -0800664 x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 if (!x)
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100666 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667
David S. Millerec18d9a2012-07-12 00:25:15 -0700668 if (type == NDISC_REDIRECT)
Duan Jiongb55b76b2013-09-04 19:44:21 +0800669 ip6_redirect(skb, net, skb->dev->ifindex, 0);
David S. Millerec18d9a2012-07-12 00:25:15 -0700670 else
671 ip6_update_pmtu(skb, net, info, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 xfrm_state_put(x);
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100673
674 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675}
676
Herbert Xu72cb6962005-06-20 13:18:08 -0700677static int ah6_init_state(struct xfrm_state *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678{
679 struct ah_data *ahp = NULL;
680 struct xfrm_algo_desc *aalg_desc;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000681 struct crypto_ahash *ahash;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682
683 if (!x->aalg)
684 goto error;
685
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 if (x->encap)
687 goto error;
688
Ingo Oeser0c600ed2006-03-20 23:01:32 -0800689 ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
Ian Morris63159f22015-03-29 14:00:04 +0100690 if (!ahp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 return -ENOMEM;
692
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000693 ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0);
694 if (IS_ERR(ahash))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 goto error;
Herbert Xu07d4ee52006-08-20 14:24:50 +1000696
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000697 ahp->ahash = ahash;
698 if (crypto_ahash_setkey(ahash, x->aalg->alg_key,
Herbert Xubc31d3b2007-10-08 17:14:34 -0700699 (x->aalg->alg_key_len + 7) / 8))
Herbert Xu07d4ee52006-08-20 14:24:50 +1000700 goto error;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900701
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 /*
703 * Lookup the algorithm description maintained by xfrm_algo,
704 * verify crypto transform properties, and store information
705 * we need for AH processing. This lookup cannot fail here
Herbert Xu07d4ee52006-08-20 14:24:50 +1000706 * after a successful crypto_alloc_hash().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 */
708 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
709 BUG_ON(!aalg_desc);
710
711 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000712 crypto_ahash_digestsize(ahash)) {
Joe Perchesf3213832012-05-15 14:11:53 +0000713 pr_info("AH: %s digestsize %u != %hu\n",
714 x->aalg->alg_name, crypto_ahash_digestsize(ahash),
715 aalg_desc->uinfo.auth.icv_fullbits/8);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 goto error;
717 }
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900718
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
Martin Willi8f8a0882009-11-25 00:29:53 +0000720 ahp->icv_trunc_len = x->aalg->alg_trunc_len/8;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900721
Herbert Xu87bdc482007-10-10 15:45:25 -0700722 x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
723 ahp->icv_trunc_len);
Herbert Xuca681452007-10-17 21:35:15 -0700724 switch (x->props.mode) {
725 case XFRM_MODE_BEET:
726 case XFRM_MODE_TRANSPORT:
727 break;
728 case XFRM_MODE_TUNNEL:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 x->props.header_len += sizeof(struct ipv6hdr);
Masahide NAKAMURAea2c47b2007-10-22 02:30:15 -0700730 break;
Herbert Xuca681452007-10-17 21:35:15 -0700731 default:
732 goto error;
733 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734 x->data = ahp;
735
736 return 0;
737
738error:
739 if (ahp) {
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000740 crypto_free_ahash(ahp->ahash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741 kfree(ahp);
742 }
743 return -EINVAL;
744}
745
746static void ah6_destroy(struct xfrm_state *x)
747{
748 struct ah_data *ahp = x->data;
749
750 if (!ahp)
751 return;
752
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000753 crypto_free_ahash(ahp->ahash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 kfree(ahp);
755}
756
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100757static int ah6_rcv_cb(struct sk_buff *skb, int err)
758{
759 return 0;
760}
761
Ian Morriscc24bec2014-08-24 21:53:11 +0100762static const struct xfrm_type ah6_type = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 .description = "AH6",
764 .owner = THIS_MODULE,
Ian Morriscc24bec2014-08-24 21:53:11 +0100765 .proto = IPPROTO_AH,
Herbert Xu436a0a42007-10-08 17:25:53 -0700766 .flags = XFRM_TYPE_REPLAY_PROT,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 .init_state = ah6_init_state,
768 .destructor = ah6_destroy,
769 .input = ah6_input,
Masahide NAKAMURAaee5adb2006-08-23 17:57:28 -0700770 .output = ah6_output,
771 .hdr_offset = xfrm6_find_1stfragopt,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772};
773
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100774static struct xfrm6_protocol ah6_protocol = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 .handler = xfrm6_rcv,
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100776 .cb_handler = ah6_rcv_cb,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 .err_handler = ah6_err,
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100778 .priority = 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779};
780
781static int __init ah6_init(void)
782{
783 if (xfrm_register_type(&ah6_type, AF_INET6) < 0) {
Joe Perchesf3213832012-05-15 14:11:53 +0000784 pr_info("%s: can't add xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 return -EAGAIN;
786 }
787
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100788 if (xfrm6_protocol_register(&ah6_protocol, IPPROTO_AH) < 0) {
Joe Perchesf3213832012-05-15 14:11:53 +0000789 pr_info("%s: can't add protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 xfrm_unregister_type(&ah6_type, AF_INET6);
791 return -EAGAIN;
792 }
793
794 return 0;
795}
796
797static void __exit ah6_fini(void)
798{
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100799 if (xfrm6_protocol_deregister(&ah6_protocol, IPPROTO_AH) < 0)
Joe Perchesf3213832012-05-15 14:11:53 +0000800 pr_info("%s: can't remove protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801
802 if (xfrm_unregister_type(&ah6_type, AF_INET6) < 0)
Joe Perchesf3213832012-05-15 14:11:53 +0000803 pr_info("%s: can't remove xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804
805}
806
807module_init(ah6_init);
808module_exit(ah6_fini);
809
810MODULE_LICENSE("GPL");
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700811MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH);